The present invention relates to a method and a system for mobile radio transmission by means of a mobile unit.
In mobile radio telephones (mobile phones) the size and the weight of the mobile phone is a decisive factor for the user. This means that if a mobile phone is smaller and lighter in weight, it can be carried more conveniently by the user and be available at all times. Meanwhile, the process of reducing the size of conventional mobile phones has reached a limit which it seems virtually impossible to overcome. The length of a mobile phone in the operational state is defined by the distance between the user""s mouth and one of his ears. For this reason, when the mobile phone is in the state in which it is not ready to be spoken into its length can be reduced further by, for example, folding it up.
Therefore, it has become apparent that the keypad is a decisive factor, in particular for the width dimension of a mobile phone. Usually, a mobile phone has the ten immediately required dialling keys together with a number of further keys for additional functions so that as a rule approximately 20 keys are arranged on a keypad on the upper side of a mobile phone. Technically it is possible to implement an overall further reduction in size of the keys of the keypad in order to reduce the size of the mobile phone, but there are natural limits to the reduction in size in that it must be possible for a finger of a hand of an adult to be able to activate a key reliably and clearly. This means that the distance between two keys must be at least such that when a key is activated an adjacent key is not undesirably activated also under circumstances. Even if, in order to reduce the size of the keypad, most additional function keys are omitted, at least the ten keys which are necessary for dialling a number together with an on/off switch are left. There is also the problem that in particular the reduction of the width of conventional mobile phones has reached a limit.
The object of the present invention is therefore to design a mobile radio transmission system in such a way that a particularly compact design of the associated mobile phone is made possible.
The invention is based on the idea that the key set can be severely reduced and the operational capability of the mobile phone is nevertheless completely ensured if access to specific functions of the mobile unit are exported, for example, into an intelligent switching service.
The invention therefore provides a method for configuring a mobile unit, the mobile unit having one or more dialling keys. All of the dialling keys are each assigned one connection destination. By activating a dialling key it is thus possible to connect exclusively to the assigned connection destination. The assignment to a central key is made here in such a way that the user of the mobile unit cannot change it directly by accessing the mobile unit.
This means that according to the invention the mobile unit does not have any keys which serve in the conventional sense for exclusively inputting a digit but rather that the mobile unit has only connection set-up keys which permit a connection set-up to a pre-programmed connection destination by means of a single activation (direct dialling keys). Be activating a central key of the mobile unit a connection is set up from the mobile unit to a central switching device, for example.
A password table which contains subscriber data with a respectively assigned password can be stored in the central switching device. After the set-up of the connection from the mobile unit to the central switching device, subscriber data and a password are then transferred from the mobile unit to the central switching device. The central switching device then compares the transferred subscriber data and/or the transferred password with the data stored in the password table. In the event that this comparison results in a correspondence between the transferred subscriber data and the transferred password with the corresponding data in the password table, the central switching device then forwards the connection of the user of the mobile unit as desired. Since, according to the invention, it is not necessary to key in a code to activate the mobile unit, the user""s security, for example in the event of a theft or other loss of the mobile unit, is ensured by the password which is to be transferred to the central switching device.
The assignment of a connection destination to in each case one of the connection set-up keys, with the exception of the central key, can be carried out here by means of a data transfer from the central switching centre to the mobile unit. It should be noted here that owing to the reduced key set, i.e. owing to the fact that only the aforesaid direct dialling keys are provided on the mobile unit, programming (assignment) of a connection destination to one of the connection set-up keys cannot be carried out at the mobile unit by the user himself.
As an alternative, or in addition, for the assignment of a connection destination to in each case one of the connection set-up keys, with the exception of the central key, the mobile unit can be inserted into a base station, the assignment then being carried out by means of a data transmission from the base station to the mobile station.
The base station can simultaneously serve as a charger station. This means that when the mobile unit is inserted into the base station an accumulator in the mobile unit can be charged at the same time.
In the password table of the central switching device, a list of preferred connection destinations can be assigned in each case to a password and/or to respective specific subscriber data. The function of a personal telephone directory is thus made possible.
A particularly simple method of operation is obtained if the activation of the central key firstly switches on the mobile unit, a further activation of the central key then sets up the connection to the central switching device, yet another activation of the central key releases the connection to the central switching device and a further activation of the central key then switches the mobile unit off again.
The mobile unit can preferably have a key lock, preventing the mobile unit from being switched on unintentionally. The key lock can bow overcome, for example, by a combination of a plurality of keys or by pressing a key for a predefined period of time.
One of the connection set-up keys can be assigned an emergency-call connection destination. By pressing once on this emergency-call key, a connection can thus easily be set up to an emergency-call organization, which is advantageous in particular for people for whom it is not possible to compose a complete number using conventional dialling keys because of physical and/or mental disabilities.
According to a further aspect of the invention, a mobile radio transmission system is provided with at least one mobile unit and one central switching centre. For performing connection set-ups, the mobile unit here has merely one or more keys, which, by being activated once, can set up a connection, in the manner of a direct dialling operation, to a connection destination which is assigned to the respective key. A central key to which a central switching device is assigned as a permanently pre-programmed connection destination is provided here. Permanently pre-programmed is intended to mean here that it is not possible, at least for the user of the mobile unit, to assign to the central key any connection destination other than the central switching device.
The central switching device can have a password table which contains subscriber data with a respectively assigned password. It is possible to provide a device by means of which, after the set-up of the connection from the mobile unit to the central switching device, subscriber data and a password can be transferred to the central switching device. A device for comparing the transferred subscriber data and/or the transferred password with the password table is then provided in the central switching device.
In the event that the call transfer by the central switching device does not take place, because, for example, the desired subscriber is currently engaged, a redial function may be provided in the mobile unit, for example by means of the central key, so that by simply activating the central key again without cooperation a renewed dialling attempt can be carried out.
In the central switching device, it is also possible to provide a device for assigning a connection destination to in each case one of the connection set-up keys, with the exception of the central key, the assignment being effected by means of a data transfer from the central switching centre to the mobile unit.
The mobile radio transmission system can be provided with a base station into which the mobile unit can be inserted in order to carry out an assignment (programming) of in each case one connection destination to one of the connection set-up keys, with the exception of the central key, by means of a data transfer from the fixed station to the mobile unit.
The base station can simultaneously be a charger station which, when the mobile unit is in the inserted state, charges an accumulator in said mobile unit. The base station can have all the functions of a conventional telephone and in particular a hands-free talking facility.
A list of preferred connection destinations, which is assigned to a password and/or to specific subscriber data, may be provided in the password table of the central switching device.